Switch actuating mechanism



Oct. 7, 1969 w 'rT R 3,470,750

SWITCH ACTUATING MECHANI SM Filed April 25, 1968 INVENTOR Franz Wetter ATTORNEYS.

United States Patent O Int. Cl. F16h 10,- G05g 5/06 US. Cl. 74-2 4 Claims ABSTRACT OF THE DISCLOSURE A switch actuating mechanism wherein a switch actuating member is connected for turning movement to a hollow shaft and a torsion rod extending through such shaft. The torsion rod is connected only at one end to the hollow shaft, and the actuating member is connected to such end. Stop means connected to the other end of the torsion rod but not to the other end of the hollow shaft limit the turning movement of the torsion bar, hollow shaft, and switch actuating member. The torsion rod thus serves to damp shocks occurring upon operation of the stop means.

BACKGROUND OF THE INVENTION The present invention relates to a switch actuating mechanism and more particularly to a switch actuating mechanism of the type having a driving spring and stop means for the actuating member.

One switch actuating mechanism known to the art includes a drive means for driving automatic actuating means in the same direction around an arc of 180 each time the actuating member is operated. The drive means in such an arrangement constitutes a plurality of drums disposed in a frame with a torsion spring provided in each drum. The rotation of the actuating member, which is effected by such drums, is limited or stopped by a locking pawl means. In this arrangement the torsion spring drums are connected directly to the drive shaft of the actuating member.

Such a switch actuating mechanism has the disadvantage that the full momentum of the driving power of the torsion spring, the actuating member drive shaft, and the actuating member itself, must be absorbed by the locking pawls upon the operation of such to limit the movements of the switch actuating member.

Another known switch actuating mechanism provides a spring drive which supplies the power for continually turning the actuating member in the same direction around an arc of 180 for each switching movement. In this arrangement, the two switch positions, on and off, are determined by a stop lever system. The stop lever system limits the movements of the actuating mechanism by providing a double arm lever and a pivotal lever system which is disposed around the double arm lever. The double arm lever, itself, is mounted on the actuating means drive shaft next to the actuating member. In order to damp the shocks caused by the stopping action in this system, shock spring elements are located on rods of the pivotal lever system. Such a switch actuating mechanism, wherein the driving components of the system are dampened during the switching operations, is relatively complicated and takes up a proportionately large amount of space.

SUMMARY OF THE INVENTION It is, therefore, the object of the present invention to provide a switch actuating mechanism of the type having a driving spring drum and a stop lever system with a ice relatively simple compact means for damping shocks which occur when the movements of an actuating member are limited by a stop means.

In brief, the present invention relates to a switch actuating mechanism having a switch actuating member which is connected to the same end of a hollow shaft that is connected to one end of a torsion rod disposed in the hollow shaft. The actuating member rotates together with the torsion rod and hollow shaft. A driving spring is interposed between a drum and the hollow shaft, and drives the hollow shaft to cause it together with thetorsion rod and actuating member to rotate. Stop means are connected ot the end of the torsion rod not connected to the hollow shaft. By this arrangement, shocks created by the stop means are absorbed by the torsion rod.

BRIEF DESCRIPTION OF THE DRAWING The single figure shown is a perspective view with a cut away portion of the switch actuating mechanism according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the sole figure shown, a spring drum 2 is provided as the housing for the drive means of the switch actuating mechanism and is disposed on a hollow shaft 1. One or more helically wound torsion springs 3 are interposed between the drum 2 and the hollow shaft 1. The torsion springs 3 are disposed with one of their respective ends engaging the hollow shaft 1 and the other of their respective ends attached to the spring drum 2.

A torsion rod 10 extends through the hollow shaft 1 and one end of the torsion rod 10 is connected to one end of the hollow shaft 1 for rotation therewith. A switch actuating member 9 is connected for rotation to the ends, respectively, of the hollow shaft 1 and the torsion rod 10 which are connected to each other.

A stop means having a double-armed abutment lever 7 is connected to the end 10a of the torsion rod 10 but not to the corresponding end of the hollow shaft 1. The abutment lever 7 in conjunction with pivotal abutment means 8 and 8', respectively, of the stop means limit the turning movement of the torsion bar 10, hollow shaft 1 and the switch actuating member 9. The abutment means are positioned apart from each other. By this arrangement the torsion rod 10 serves to damp shocks which occur upon the operation of the stop means. The stop lever 7 prevents further rotation of the rotation rod 10 upon abuttingly engaging either the abutment means 8 or 8 upon their being moved inwardly so that in rest position of the switch, the lever arms 8a and 8a lie against the respective release spindles 12, 12', under the influence of the respective springs 11, 11'. To operate the switch, the abutment means 8 or 8 are moved outwardly, this being done by rotating the respective spindle, e.g., the spindle 12, until its cut-away portion moves into alignment with the path in which the spring 11 urges the lever arm 8a to rotate, so that the lever arm 8a pivots in counter-clockwise direction, as viewed in the driving and, through the intermediary of the screw 13, carries with it the abutment 8 whereupon lever 7 is free to rotate 180 until it strikes the other abutment 8'.

Referring to the torsion rod 10, the ends 10a and 10b thereof each have an outside diameter substantially equal to the inside diameter of the hollow shaft 1. The portion of the torsion rod 10 intermediate the ends 10a and 10b has an outside diameter which is less than the inside diameter of the hollow shaft 1. The intermediate portion of the torsion rod 10, therefore, is relatively elastic compared to its remainder.

The torsion springs 3 are wound by means of a gear drive 4 which includes a gear mounted on the drum 2. The gear drive 4 can either 'be driven by a motor 5 or by a manually operated crank 6, as desired. The force of the wound spring 3 is transferred to the actuating member 9 by way of the hollow shaft 1 and end b connected to hollow shaft 1 and actuating member 9.

In operation the double armed abutment lever 7 is normally held by pivotal abutment means 8 and 8. When the switch is to be operated, the abutment means 8 is, as stated above, moved outwardly thus making it possible for the double arm abutment lever 7 to rotate 180 to the next abutment means 8. The driving force of the springs 3 is transmitted by way of the hollow shaft 1 and the entire length of the torsion bar 10 to the double armed abutment lever 7. Occurring simultaneously with such rotation, the actuating member 9, which drives the movable switch components, is driven via the relatively inelastic portion 10b of the torsion bar 10. Upon the movable switch components reaching their intended switching position, one arm of the double armed abutment lever 7 abuttingly engages the abutment means 8 or 8', which ever the case may be. The abutment means 8 or 8 limit the movement of the movable switch components causing the shocks or vibrations in the switch actuating mechanism. The torsion bar 10 which is intermediately positioned between the abutment means 8 and 8' serves as a damping member or means which absorbs such shocks as occur.

The present invention, therefore, provides a simple, compact switch actuating mechanism which is provided with means for absorbing the shocks caused during its operation.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

I claim:

1. A switch actuating mechanism comprising, in combination:

(a) a hollow shaft;

(b) a drum surrounding said shaft;

(c) torsion spring means interposed between said drum and said hollow shaft;

(d) a torsion rod extending through said hollow shaft,

one end of said torsion rod and one end of said hollow shaft being connected to each other for rotation with each other;

(e) a switch actuating member connected for turning movement together with said one end of said hollow shaft and said one end of said torsion rod; and

(f) stop means connected to the other end of said torsion bar but not to the other end of said hollow shaft for limiting turning movement of said torsion bar, said hollow shaft and said switch actuating member, in consequence of which said torsion rod serves to damp shocks occurring upon the operation of said stop means.

2. The combination defined in claim 1 wherein said stop means comprise an abutment lever connected to said other end of said torsion bar, and abutment means located in the path of movement of said abutment lever.

3. The combination defined in claim 2 wherein the ends of said torsion rod have an out-side diameter substantially equal to the inside diameter of said hollow shaft.

4. The combination defined in claim 3 wherein said torsion rod has, intermediate its ends, a portion whose outside diameter is less than the inside diameter of said hollow shaft.

References Cited UNITED STATES PATENTS 3,183,317 5/1965 McCartney 74-527 3,289,790 12/1966 Ivins -39 3,364,752 1/1968 Hjerrnstad et al. 742 3,375,904 4/1968 Kaplan 18539 FRANK C. MATTERN, JR., Primary Examiner F. D. SHOEMAKER, Assistant Examiner US. Cl. X.R. 

